There are 40 weeks of lessons in the book but how much of the book are you meant to teach to the Prep level and each other level to Grade 6 ?
The answer to that is at the teacher's, and school's, discretion.
The "weeks" would only represent real weeks if the class is fairly capable year 5 or 6 and the time allocation is about 2-2.5 hours a week. In that case, the course can fit into one year. Normal time allocations are significantly less than that and younger children take longer to memorize vocabulary (although they have an excellent "ear" for pronunciation).
Other variables include the linguistic background of the children and the teacher, how much curriculum integration is used (like calling the roll in Esp-o, counting in sports in Esp-o ... and how long is spent on intercultural exploration.
Teachers will never "run out" of LOTE to do, using this program, because it provides all of the grammar and enough vocabulary to enable endless reading, writing, speaking and listening activities, both literary and instrumental, and the contacts to support the teacher in leading them. In particular, it provides opportunities to make intercultural relationships in dozens of diverse cultures, which can profitably fill as much time as will ever be available.
For the purposes of coordinating provision within a school, I recommend that teachers annotate their copy of the book, to indicate what has been done (and to what effect) and what has been omitted, and that the book is passed on to the next teacher at the end of the year. This will provide better continuity than a theoretical division which would not be accurately adhered to in any case.
Thanks again for the question, Steve